Dry-cell.



F. L. WHITE.

DRY CELL.

APPLICATION msu sm. l2. |914.

1 1 96,999. Patented Sept. 5, 1916.

WAmPnonr Ccurrms ELASTIC PrrcH Ccm'rrm WITH Pnu'rnn'rmGWAx Z IN VEN TOR.

WTNESSES" FHBB BRICK I... WHITE dV/Q/LOM l BY QQ/w.

TTORNE Y UNITED STATES PATENT OFFICE.

FREDERICK L. WHITE, 0F LAKEWOOD, OHIO, ASSIGNOB T0 NATIONAL CARBONCOMPANY, A CORPORATION 0F NEW JERSEY.

DRY CELL.

speelcation o! Letten Patent.

Patented Sept. 5, 1916.

To all whom it may concern.'

Be it known that I, FREDERICK L. Wm'rn, a citizen of the United States,residing at Lakewood, in the county of Cuyahoga and State of Ohio, haveinvented a certain new and useful Improvement in Dry Cells, of which thefollowing is a full, clear, and exact description.`

This invention relates to a waterproof insulating coatin for dry cellshavin pasteboard jackets. Vhen used in moist c imates, motor boats,etc., the ackets sometimes are wetted, especially at t e bottom to suchan extent that they become electrically conductive and short circuit thezinc container electrodes of adjacent cells. Also the water causes the'oints to become unglued and the jackets-to all oil'.

All prior methods of waterproofing are disadvantageous because they aretoo expensive, do not perform their functions comletely, or give thecells a oor a pearance. iiculties occur principali wit the bottom of thejackets when the attery box case becomes partially filled with water.After setting in water for any considerable time the water soaks through:any portion where the coating has been damaged, and to obviate thistroub e I treat a dry cell as illustrated in the accompanying drawingsin which Figure 1 isa perspective view of a dry cell treated by mywaterproofing process. Fig. 2 is a partial sectional view of the bottomof the jacket.

Referring to the drawings, 1 represents the pasteboard jacket and 2 thepaper cap which closes the bottom. The bottom of the jacket is dippedinto a heated waterproofing compound 3 consisting of aproximately 49% ofhard pitch, 44% of so pitch and 7 of scale wax to cover the capcompletely. When this compound cools it forms an elastic wate roofcoating entirely covering the outside o the cap. This coating isrelatively thick and suilciently elastic so that it will not chip 01T.

Althou h I have set forth a certain comosition or coatin the cap, itwill be evient that other' suitable materials or compositions maybeused. For instance, in cool weather I use a compound having a aterkpercentage of soft pitch, as 44% .o hard pitch, 49% of soft pitch and7% of scale wax. Under these climatic conditions this compound has thesame properties as the lirst material. Other compounds may be used but Iprefer the composition set forth.

When the previous compounds alone are used they become sticky in warmweather and cause the bottom of the cell to adhere to paper, straw andother packing material' in their shipment, giving them an unsightly.appearance. To prevent this, as well as to make the rest of the 'acketwaterproof, I immerse the entire jac et in melted scale wax to form acoating 4 over the entire article. This coating also prevents the pitchfrom being chipped off when it becomes hardened in cold we Lther.v Atemperature ofv 70 degrees centigrade for the melted wax is found to begererable for impregnating the jackets, use at higher temperatures theglue used in making the jacket is deleteriously affected, and at lowertemperatures the impregnation cannot be carried on as well. Itfwill beevident that other well known waterproof coatings may be used instead ofscale wax.

After the jacket has been prepared in the manner described, the dry cellis inserted therein and the entire article is again immersed in meltedscale wax to completel cover it with a waterproof coating, which givesthe cell a neat lossy appearance. The scale wax coating ing transparent,the label is printed directly on the jacket in the usual way, and anextra label is not required as with' opaque coatings. The cell isespecially advantageous where only a small amount 0f water is present inthe bottom of the battery box. In most cases this condition, rather thanthe complete immersion of the cell, is encountered. A cell having acoating of pitch and wax at the bottom will withstand the action ofwater indefinitely and can be more cheaply made than a cell entirelycovered with a compound such as the pitch material described. Although Imay coat the entire cell with this compound, it is disadvantageous onaccount of the extra label required, as well as the extra expense.

Having described my invention, what I claim is 1. The process ofwater-proofing a dry cell jacket having a cap for closing the bottom,which consists in applying a coating of 'nsk elastic material to coverthe cap and afterward applying a coating of Wax to the exterior of thejacket and cap.

2. The process of Water-proong a dry cell' jacket having a bottom cap,which con sists in dipping the jacket in melted pitch adapted to becomeelastic upon cooling, and then impregnating the entire jacket byimmersing in wax heated to a temperature of approximately 700 C.

3. The process of water-proofing a dry cell which consists in coatingthe bottom portion of a jacket with an elastic insulating material,impregnating the entire jacket with wax, inserting the cell in thejacket and immersing the entire article in melted Wax.

4. A water-proof pasteboard jacket for a dry cell having a bottom, anelastic coating on said bottom, and a coating of Wax applied to thejacket and first mentioned coating.

5. A dry cell having an inclosing jacket, a bottom cap, a coating ofelastic material on the bottom of said jacket extending above thejunction between the cap and jacket, and a coating of Wax applied 'tosaid jacket and first mentioned coating.

6. A dry cell having an inc-losing acket, a

bottom cap, a coat of elastic material on the FREDERICK L. WHITE.

Witnesses J W. FERGUSON, I-I. G. GRoVER.

